1. Field of the Invention
The present invention relates to a backlight in which a reflector is secured to a chassis disposing a mounted substrate mounting light emitting diodes between the reflector and the chassis by a lamp clip for holding lamps and the mounted substrate is connected to a drive substrate outside the chassis and also relates to a liquid crystal display device provided with the backlight and a liquid crystal panel.
2. Description of the Related Art
A backlight having lamps such as CCFLs (cold cathode type fluorescent lamps) and LEDs (light emitting diodes) is utilized in a liquid crystal display device. As disclosed in the Japanese Patent Application Laid-Open No. 2004-318176, the backlight supports lamps above a reflective sheet by means of a clip (lamp clip). FIG. 1 is a sectional view illustrating an exemplary arrangement and construction of the backlight in a simplified manner.
In the example as shown in FIG. 1, a reflective sheet 30a is secured to a chassis 36a disposing an LED substrate (mounted substrate) 35a mounting LEDs (light emitting diodes) 33 therebetween by means of a clip 10a and lamps 34 such as CCFLs and the like are supported above the reflective sheet 30a. The clip 10a is provided with an upper protrusion 20a projected upward from the reflective sheet 30a. An optical sheet 38 is disposed above the upper protrusion 20a and a liquid crystal panel 44 is positioned thereon. The clip 10a is white as in a surface of the reflective sheet 30a and reflects light.
The LEDs 33 mounted on the LED substrate 35a is configured to be driven by a drive circuit of an LED drive substrate (drive substrate) 44a outside the chassis 36a. Also a color sensor such as a photodiode (light receiving means) 42 is mounted on the LED substrate 35a. The photodiode 42 is connected to the LED drive substrate 44a. The photodiode 42 transmits color information to the LED drive substrate 44a and based on the color information the LED drive substrate 44a drives the LEDs 33 to adjust colors of light radiated onto the liquid crystal panel 40 into target colors.
However, as the photodiode 42 is mounted on the LED substrate 35a the LEDs 33 tend to have effects on the photodiode 42 nearby. The backlight in accordance with the prior art has a problem that colors of the light radiated on the liquid crystal panel 40 could not be detected accurately. Also, another problem is that the backlight in accordance with the prior art requires an aperture on the reflective sheet 30a for each photodiode 42 as well as a wiring arrangement to connect the photodiode 42 to the LED drive substrate 44a. 